1. Field of the Invention
The instant invention relates to tilt switches. More particularly, the instant invention relates to tilt switches which close contacts within the switch with a liquid which conducts electric current.
2. Technical Considerations and Prior Art
There are numerous tilt switches now on the market which utilize a liquid which conducts electricity. Generally these switches are configured with a pair of spaced contacts disposed in an enclosure along with a quantity of conducting liquid, which liquid is usually mercury. The mercury is attracted by gravity to the bottom of the enclosure. When the enclosure is tilted, the mercury tends to remain at the bottom of the enclosure and flows to seek its lowest level. If the enclosure is tilted far enough so that the mercury fills the space between the contacts, the switch is closed so that current flows from one contact, through the mercury to the other contact. As is readily apparent from the following list of U.S. Patents, there are numerous configurations and uses for the afore-described type of switch:
______________________________________ 2,745,091 Leffler 2,823,367 Huron 3,074,049 Saliba et al 3,204,233 Olliff 3,276,007 White 3,656,100 Beltrami 3,683,423 Crapanzano 3,699,485 Lindermeyer 3,710,371 Whalen, et al 3,753,175 Gillette 3,787,641 Hughes 3,921,128 Snead 4,221,278 Ponzo ______________________________________
Of the above-identified patents, perhaps U.S. Pat. No. 3,787,647 is the closest in concept to the instant invention in that this patent discloses a pair of circular electrodes or contacts which are closed by a globule of mercury. In this particular patent, however, the globule of mercury is initially displaced from both contacts. The globule of mercury has to roll in the conical channel 33 to the top edge of the conical channel in order to close contacts 27. With this switch, there must be considerable tilting before the contacts 27 can be closed. Moreover, there is the chance that the mercury globule will simply flatten so far that it will not have sufficient height to close the gap between the two electrodes 27. Accordingly, the switch of U.S. Pat. No. 3,787,647 is not entirely satisfactory for all purposes.
In view of the aforementioned considerations, there is a need for a switch which will detect tilting in any direction throughout 360 degrees of orientation while at the same time being configured so that it is responsive to very slight degrees of tilt if necessary. Moreover, there is a need for a tilt switch which is sufficiently flexible in its design to accomodate various degrees of tilt and various specific needs and considerations.